DESCRIPTION: The investigator will determine the functions of all genes in the pdu operon that allows propanediol/tetrathionate-dependent anaerobic growth. This will involve completion of the DNA sequence of the pdu operon, a characterization of the pdu genes involved in the conversion of cyanocobalamin to Ado-cobalamin, a characterization of the unique organelle (CLOs carboxysome-like organelles of Salmonella), and identification of the genes that catalyze the catabolism of propanediol and determination of whether pdu genes are involved in cobalamin exchange. They will also extend their studies on the fermentation and anaerobic respiration of propanediol and ethanolamine and, given time, they will determine the structure of a putative novel corrinide involved in tetrathionate reduction.